No one likes loading errors.
Luckily, clearing your Unity Player's cache should clear up this pesky problem and get you back in the game. Use the following steps to clear your cache:
- Visit http://webplayer.unity3d.com/setup to view a list of what is currently cached on your hard disk.
- Click on the title of the game in question and then click the Delete [GAME]... button.
- A warning prompt will appear stating all data will have to be redownloaded.
- Click the Delete [GAME] button to confirm.
- Try loading the game again and you should be up and running.